Plasmonic electromagnetically-induced transparency in symmetric structures

TL;DR

This paper demonstrates that plasmonic electromagnetically-induced transparency can occur in symmetric structures through second-order magnetic-plasmon resonance, challenging the common belief that asymmetry is necessary.

Contribution

It reveals that symmetric structures can exhibit plasmonic EIT via second-order MPR, expanding the understanding of plasmonic coherent interference mechanisms.

Findings

Symmetric structures can support plasmonic EIT.

Second-order MPR enables dark mode excitation in symmetric setups.

The study enhances the theoretical understanding of plasmonic interference.

Abstract

A broken symmetry is generally believed to be a prerequisite of plasmonic electromagnetically-induced transparency (EIT), since the asymmetry renders the excitation of the otherwise forbidden dark mode possible. Nevertheless, according to the picture of magnetic-plasmon resonance (MPR) mediated plasmonic EIT, we show that the plasmonic EIT can be achieved even in the symmetric structures based on the second-order MPR. This sharpens our understanding of the existing concept, but also a profound insight into the plasmonic coherent interference in the near-field zone.